1. Field of the Invention
This invention relates to a hose snap-action joint.
2. Description of the Prior Art
When connecting hoses or connecting a hose with a connection opening of a manifold, a hose snap-action joint is employed.
Many conventional hose snap-action joints have been known, one of which is disclosed in Japanese Unexamined Utility Model Publication (KOKAI) No. 56281/1983. As shown in FIG. 10, the conventional hose snap-action joint comprises a pair of cylinder-shaped joint fixtures 100 and 102. The joint fixtures 100 and 102 are engaged with each other, thereby connecting hoses. One of the joint fixtures 100 is provided with a plurality of balls 104 projectable in the radial direction, and the other joint fixture 102 is provided with an annular groove 106 for admitting the balls 104. The joint fixtures 100 and 102 are engaged in the axial direction by way of the balls 104 and the annular groove 106, thereby connecting the joint fixtures 100 and 102. When disconnecting the joint fixtures 100 and 102, the balls 104 are recessed in a groove 112 formed on the inner surface of a ring 110 by retracting the ring 110, urged by a spring 108, in the axial direction. The joint fixtures 100 and 102 are thus disconnected.
However, in the hose snap-action joint of this type, all of the components including the pair of joint fixutres 100 and 102 should be made of metal in order to make the locking and unlocking mechanism comprising the balls 104 and the annular groove 106 smoothly operable. Thus, the entire joint fixtures 100 and 102 which have complicated shapes should be machined, and the manufacturing cost becomes expensive, because the total number of the assembly steps, including the assembly of the balls 104, has increased.
Further, in the structure of the hose snap-action joint of this type, the pair of joint fixtures 100 and 102 are prevented from coming-off by the engagement between the balls 104 and the annular groove 106. Accordingly, stress is exerted concentratedly on the engaging positions of the balls 104 and the annular groove 106.
Furthermore, the pair of joint fixtures 100 and 102 allows an easy connecting operation. However, the joint fixtures 100 and 102 are disconnected with ease when the ring 110 is operated by accident.
In addition, when the conventional hose snap-action joint is used in the outdoors, the problem of corrosion always associate with the conventional hose snap-action joint because all of the joint component members are made of metal.
By the way, the hose snap-action joint of the above-mentioned metal-made ball joint type has been applied to a joint for a high pressure hose of 140 kgf/cm.sup.2 or more. However, in the conventional application, the hose snap-action joint has been applied also to a joint for a relatively lower pressure of 70 to 100 kgf/cm.sup.2 as it is. In this case, however, the application of the hose snap-action joint, adapted to the high pressure hose application, to the lower pressure hose results in an excessive quality and an expensive manufacturing cost, thereby incurring losses.